/Engine/Source/Runtime/MovieScene/Public/EntitySystem/MovieSceneEntityManager.h
Combine the components from one entity into another, overwriting any pre-existing component values. Does not free any entities.
void CombineComponents ( [FMovieSceneEntityID](API\Runtime\MovieScene\EntitySystem\FMovieSceneEntityID) DestinationEntityID, [FMovieSceneEntityID](API\Runtime\MovieScene\EntitySystem\FMovieSceneEntityID) SourceEntityID, const [FComponentMask](API\Runtime\MovieScene\EntitySystem\FComponentMask) * OptionalMask )